The present invention relates generally to film cartridges and to a method and apparatus for opening such cartridges to permit removal of a film member. More specifically, the invention relates to a film cartridge for enclosing a photosensitive film in a disk format and to a method and apparatus for opening the cartridge to permit removal of the film disk for photofinishing.
Description of the Prior Art
Film cartridges and magazines having light-tight chambers for supporting photosensitive film members are generally well known in the photographic art. As many of the early film cartridges were relatively expensive to produce, they were usually adapted to be reloaded by photofinishers. Sections of the film cartridges were usually joined by removable fasteners which permitted the cartridge to be opened without damage or destruction of the sections. For example, the early cartridge or film holder disclosed in U.S. Pat. No. 2,446,200 comprised two generally parallel wall sections which were joined by a plurality of hollow rivets positioned around the peripheral edge. Following exposure of images onto the enclosed film disk, the holder was sent to a photofinisher for removal of the exposed film disk and reloading of the film holder with an unexposed film disk. To open the film holder, the hollow rivets were removed by a punch press and the sections of the holder were separated in an undisclosed manner to permit removal of the film disk from the chamber.
Many of the film cartridges produced in more recent years have not been adapted for reloading as the walls of the cartridges have been permanently sealed to permit the cartridges to withstand considerable abuse and tampering. To remove the film member from such cartridges, mechanical opening devices usually cut or tear away a portion of the cartridge to permit access to the film member. Representative devices for opening such cartridges to permit removal of the film members are disclosed in U.S. Pat. Nos. 3,265,263; 3,429,042; 3,487,966; 3,550,877; 3,579,801; 3,580,443; and 3,584,380. While many of the prior art devices offer desirable features, it will become apparent from the following specification that such devices lack significant advantages presented by the structure of the present invention. In most cases, for example, the prior openers are not entirely suitable for opening thin film cartridges having walls joined together proximate their peripheral edges.
Also known in the prior art are film transparency holders which have some characteristics similar to film cartridges. For example, U.S. Pat. No. 3,341,960 and French Pat. No. 1,311,727 disclose transparency holders having opposed, generally parallel frame members which support a processed film transparency. As disclosed in these patents, a processed film transparency can be moved through an enlarged slot defined between the opposed frame members of the transparency holder. To enlarge the slot and permit insertion or removal of the transparency, a spreading mandrel is inserted through passages formed in a frame member and into contact with the opposed frame member. The mandrel then displaces the opposed frame member and enlarges the opening sufficiently to permit movement of the transparency through the opening. Although, with commercial embodiments of devices using such an arrangement, it is known to insert a guide channel adjacent to or into the enlarged opening between the frame members to guide the film, such guide channels do not intentionally tear the two frame members apart or rupture the seal as the integrity of the transparency holder must be maintained to fulfill its intended purpose. While it is known from U.S. Pat. No. 2,803,077 and 2,837,854, that a film member may be removed from a transparency holder by application of a sharp instrument between the joined frame members, there is no suggestion in the prior art of the combination of these teachings to open a film cartridge, as will become evident from the following description of the invention.